intel/compiler: Add a flag to avoid compacting push constants

In vec4, we can just not run the pass.  In fs, things are a bit more
deeply intertwined.

Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
This commit is contained in:
Jason Ekstrand
2019-10-31 15:57:52 -05:00
parent aecde23519
commit d1c4e64a69
6 changed files with 177 additions and 152 deletions

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@@ -673,6 +673,7 @@ iris_screen_create(int fd, const struct pipe_screen_config *config)
screen->compiler->shader_perf_log = iris_shader_perf_log;
screen->compiler->supports_pull_constants = false;
screen->compiler->supports_shader_constants = true;
screen->compiler->compact_params = false;
iris_disk_cache_init(screen);

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@@ -119,6 +119,12 @@ struct brw_compiler {
* whether nir_opt_large_constants will be run.
*/
bool supports_shader_constants;
/**
* Whether or not the driver wants uniform params to be compacted by the
* back-end compiler.
*/
bool compact_params;
};
/**

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@@ -2307,159 +2307,190 @@ fs_visitor::assign_constant_locations()
return;
}
struct uniform_slot_info slots[uniforms];
memset(slots, 0, sizeof(slots));
if (compiler->compact_params) {
struct uniform_slot_info slots[uniforms];
memset(slots, 0, sizeof(slots));
foreach_block_and_inst_safe(block, fs_inst, inst, cfg) {
for (int i = 0 ; i < inst->sources; i++) {
if (inst->src[i].file != UNIFORM)
foreach_block_and_inst_safe(block, fs_inst, inst, cfg) {
for (int i = 0 ; i < inst->sources; i++) {
if (inst->src[i].file != UNIFORM)
continue;
/* NIR tightly packs things so the uniform number might not be
* aligned (if we have a double right after a float, for
* instance). This is fine because the process of re-arranging
* them will ensure that things are properly aligned. The offset
* into that uniform, however, must be aligned.
*
* In Vulkan, we have explicit offsets but everything is crammed
* into a single "variable" so inst->src[i].nr will always be 0.
* Everything will be properly aligned relative to that one base.
*/
assert(inst->src[i].offset % type_sz(inst->src[i].type) == 0);
unsigned u = inst->src[i].nr +
inst->src[i].offset / UNIFORM_SLOT_SIZE;
if (u >= uniforms)
continue;
unsigned slots_read;
if (inst->opcode == SHADER_OPCODE_MOV_INDIRECT && i == 0) {
slots_read = DIV_ROUND_UP(inst->src[2].ud, UNIFORM_SLOT_SIZE);
} else {
unsigned bytes_read = inst->components_read(i) *
type_sz(inst->src[i].type);
slots_read = DIV_ROUND_UP(bytes_read, UNIFORM_SLOT_SIZE);
}
assert(u + slots_read <= uniforms);
mark_uniform_slots_read(&slots[u], slots_read,
type_sz(inst->src[i].type));
}
}
int subgroup_id_index = get_subgroup_id_param_index(stage_prog_data);
/* Only allow 16 registers (128 uniform components) as push constants.
*
* Just demote the end of the list. We could probably do better
* here, demoting things that are rarely used in the program first.
*
* If changing this value, note the limitation about total_regs in
* brw_curbe.c.
*/
unsigned int max_push_components = 16 * 8;
if (subgroup_id_index >= 0)
max_push_components--; /* Save a slot for the thread ID */
/* We push small arrays, but no bigger than 16 floats. This is big
* enough for a vec4 but hopefully not large enough to push out other
* stuff. We should probably use a better heuristic at some point.
*/
const unsigned int max_chunk_size = 16;
unsigned int num_push_constants = 0;
unsigned int num_pull_constants = 0;
push_constant_loc = ralloc_array(mem_ctx, int, uniforms);
pull_constant_loc = ralloc_array(mem_ctx, int, uniforms);
/* Default to -1 meaning no location */
memset(push_constant_loc, -1, uniforms * sizeof(*push_constant_loc));
memset(pull_constant_loc, -1, uniforms * sizeof(*pull_constant_loc));
int chunk_start = -1;
struct cplx_align align;
for (unsigned u = 0; u < uniforms; u++) {
if (!slots[u].is_live) {
assert(chunk_start == -1);
continue;
/* NIR tightly packs things so the uniform number might not be
* aligned (if we have a double right after a float, for instance).
* This is fine because the process of re-arranging them will ensure
* that things are properly aligned. The offset into that uniform,
* however, must be aligned.
*
* In Vulkan, we have explicit offsets but everything is crammed
* into a single "variable" so inst->src[i].nr will always be 0.
* Everything will be properly aligned relative to that one base.
*/
assert(inst->src[i].offset % type_sz(inst->src[i].type) == 0);
unsigned u = inst->src[i].nr +
inst->src[i].offset / UNIFORM_SLOT_SIZE;
if (u >= uniforms)
continue;
unsigned slots_read;
if (inst->opcode == SHADER_OPCODE_MOV_INDIRECT && i == 0) {
slots_read = DIV_ROUND_UP(inst->src[2].ud, UNIFORM_SLOT_SIZE);
} else {
unsigned bytes_read = inst->components_read(i) *
type_sz(inst->src[i].type);
slots_read = DIV_ROUND_UP(bytes_read, UNIFORM_SLOT_SIZE);
}
assert(u + slots_read <= uniforms);
mark_uniform_slots_read(&slots[u], slots_read,
type_sz(inst->src[i].type));
}
}
/* Skip subgroup_id_index to put it in the last push register. */
if (subgroup_id_index == (int)u)
continue;
int subgroup_id_index = get_subgroup_id_param_index(stage_prog_data);
if (chunk_start == -1) {
chunk_start = u;
align = slots[u].align;
} else {
/* Offset into the chunk */
unsigned chunk_offset = (u - chunk_start) * UNIFORM_SLOT_SIZE;
/* Only allow 16 registers (128 uniform components) as push constants.
*
* Just demote the end of the list. We could probably do better
* here, demoting things that are rarely used in the program first.
*
* If changing this value, note the limitation about total_regs in
* brw_curbe.c.
*/
unsigned int max_push_components = 16 * 8;
if (subgroup_id_index >= 0)
max_push_components--; /* Save a slot for the thread ID */
/* Shift the slot alignment down by the chunk offset so it is
* comparable with the base chunk alignment.
*/
struct cplx_align slot_align = slots[u].align;
slot_align.offset =
(slot_align.offset - chunk_offset) & (align.mul - 1);
/* We push small arrays, but no bigger than 16 floats. This is big enough
* for a vec4 but hopefully not large enough to push out other stuff. We
* should probably use a better heuristic at some point.
*/
const unsigned int max_chunk_size = 16;
align = cplx_align_combine(align, slot_align);
}
unsigned int num_push_constants = 0;
unsigned int num_pull_constants = 0;
/* Sanity check the alignment */
cplx_align_assert_sane(align);
push_constant_loc = ralloc_array(mem_ctx, int, uniforms);
pull_constant_loc = ralloc_array(mem_ctx, int, uniforms);
if (slots[u].contiguous)
continue;
/* Default to -1 meaning no location */
memset(push_constant_loc, -1, uniforms * sizeof(*push_constant_loc));
memset(pull_constant_loc, -1, uniforms * sizeof(*pull_constant_loc));
/* Adjust the alignment to be in terms of slots, not bytes */
assert((align.mul & (UNIFORM_SLOT_SIZE - 1)) == 0);
assert((align.offset & (UNIFORM_SLOT_SIZE - 1)) == 0);
align.mul /= UNIFORM_SLOT_SIZE;
align.offset /= UNIFORM_SLOT_SIZE;
int chunk_start = -1;
struct cplx_align align;
for (unsigned u = 0; u < uniforms; u++) {
if (!slots[u].is_live) {
assert(chunk_start == -1);
continue;
unsigned push_start_align = cplx_align_apply(align, num_push_constants);
unsigned chunk_size = u - chunk_start + 1;
if ((!compiler->supports_pull_constants && u < UBO_START) ||
(chunk_size < max_chunk_size &&
push_start_align + chunk_size <= max_push_components)) {
/* Align up the number of push constants */
num_push_constants = push_start_align;
for (unsigned i = 0; i < chunk_size; i++)
push_constant_loc[chunk_start + i] = num_push_constants++;
} else {
/* We need to pull this one */
num_pull_constants = cplx_align_apply(align, num_pull_constants);
for (unsigned i = 0; i < chunk_size; i++)
pull_constant_loc[chunk_start + i] = num_pull_constants++;
}
/* Reset the chunk and start again */
chunk_start = -1;
}
/* Skip subgroup_id_index to put it in the last push register. */
if (subgroup_id_index == (int)u)
continue;
/* Add the CS local thread ID uniform at the end of the push constants */
if (subgroup_id_index >= 0)
push_constant_loc[subgroup_id_index] = num_push_constants++;
if (chunk_start == -1) {
chunk_start = u;
align = slots[u].align;
/* As the uniforms are going to be reordered, stash the old array and
* create two new arrays for push/pull params.
*/
uint32_t *param = stage_prog_data->param;
stage_prog_data->nr_params = num_push_constants;
if (num_push_constants) {
stage_prog_data->param = rzalloc_array(mem_ctx, uint32_t,
num_push_constants);
} else {
/* Offset into the chunk */
unsigned chunk_offset = (u - chunk_start) * UNIFORM_SLOT_SIZE;
/* Shift the slot alignment down by the chunk offset so it is
* comparable with the base chunk alignment.
*/
struct cplx_align slot_align = slots[u].align;
slot_align.offset =
(slot_align.offset - chunk_offset) & (align.mul - 1);
align = cplx_align_combine(align, slot_align);
stage_prog_data->param = NULL;
}
assert(stage_prog_data->nr_pull_params == 0);
assert(stage_prog_data->pull_param == NULL);
if (num_pull_constants > 0) {
stage_prog_data->nr_pull_params = num_pull_constants;
stage_prog_data->pull_param = rzalloc_array(mem_ctx, uint32_t,
num_pull_constants);
}
/* Sanity check the alignment */
cplx_align_assert_sane(align);
if (slots[u].contiguous)
continue;
/* Adjust the alignment to be in terms of slots, not bytes */
assert((align.mul & (UNIFORM_SLOT_SIZE - 1)) == 0);
assert((align.offset & (UNIFORM_SLOT_SIZE - 1)) == 0);
align.mul /= UNIFORM_SLOT_SIZE;
align.offset /= UNIFORM_SLOT_SIZE;
unsigned push_start_align = cplx_align_apply(align, num_push_constants);
unsigned chunk_size = u - chunk_start + 1;
if ((!compiler->supports_pull_constants && u < UBO_START) ||
(chunk_size < max_chunk_size &&
push_start_align + chunk_size <= max_push_components)) {
/* Align up the number of push constants */
num_push_constants = push_start_align;
for (unsigned i = 0; i < chunk_size; i++)
push_constant_loc[chunk_start + i] = num_push_constants++;
} else {
/* We need to pull this one */
num_pull_constants = cplx_align_apply(align, num_pull_constants);
for (unsigned i = 0; i < chunk_size; i++)
pull_constant_loc[chunk_start + i] = num_pull_constants++;
/* Up until now, the param[] array has been indexed by reg + offset
* of UNIFORM registers. Move pull constants into pull_param[] and
* condense param[] to only contain the uniforms we chose to push.
*
* NOTE: Because we are condensing the params[] array, we know that
* push_constant_loc[i] <= i and we can do it in one smooth loop without
* having to make a copy.
*/
for (unsigned int i = 0; i < uniforms; i++) {
uint32_t value = param[i];
if (pull_constant_loc[i] != -1) {
stage_prog_data->pull_param[pull_constant_loc[i]] = value;
} else if (push_constant_loc[i] != -1) {
stage_prog_data->param[push_constant_loc[i]] = value;
}
}
/* Reset the chunk and start again */
chunk_start = -1;
}
/* Add the CS local thread ID uniform at the end of the push constants */
if (subgroup_id_index >= 0)
push_constant_loc[subgroup_id_index] = num_push_constants++;
/* As the uniforms are going to be reordered, stash the old array and
* create two new arrays for push/pull params.
*/
uint32_t *param = stage_prog_data->param;
stage_prog_data->nr_params = num_push_constants;
if (num_push_constants) {
stage_prog_data->param = rzalloc_array(mem_ctx, uint32_t,
num_push_constants);
ralloc_free(param);
} else {
stage_prog_data->param = NULL;
}
assert(stage_prog_data->nr_pull_params == 0);
assert(stage_prog_data->pull_param == NULL);
if (num_pull_constants > 0) {
stage_prog_data->nr_pull_params = num_pull_constants;
stage_prog_data->pull_param = rzalloc_array(mem_ctx, uint32_t,
num_pull_constants);
/* If we don't want to compact anything, just set up dummy push/pull
* arrays. All the rest of the compiler cares about are these arrays.
*/
push_constant_loc = ralloc_array(mem_ctx, int, uniforms);
pull_constant_loc = ralloc_array(mem_ctx, int, uniforms);
for (unsigned u = 0; u < uniforms; u++)
push_constant_loc[u] = u;
memset(pull_constant_loc, -1, uniforms * sizeof(*pull_constant_loc));
}
/* Now that we know how many regular uniforms we'll push, reduce the
@@ -2475,24 +2506,6 @@ fs_visitor::assign_constant_locations()
push_length += range->length;
}
assert(push_length <= 64);
/* Up until now, the param[] array has been indexed by reg + offset
* of UNIFORM registers. Move pull constants into pull_param[] and
* condense param[] to only contain the uniforms we chose to push.
*
* NOTE: Because we are condensing the params[] array, we know that
* push_constant_loc[i] <= i and we can do it in one smooth loop without
* having to make a copy.
*/
for (unsigned int i = 0; i < uniforms; i++) {
uint32_t value = param[i];
if (pull_constant_loc[i] != -1) {
stage_prog_data->pull_param[pull_constant_loc[i]] = value;
} else if (push_constant_loc[i] != -1) {
stage_prog_data->param[push_constant_loc[i]] = value;
}
}
ralloc_free(param);
}
bool

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@@ -633,6 +633,9 @@ set_push_constant_loc(const int nr_uniforms, int *new_uniform_count,
void
vec4_visitor::pack_uniform_registers()
{
if (!compiler->compact_params)
return;
uint8_t chans_used[this->uniforms];
int new_loc[this->uniforms];
int new_chan[this->uniforms];

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@@ -560,6 +560,7 @@ anv_physical_device_init(struct anv_physical_device *device,
device->compiler->constant_buffer_0_is_relative =
device->info.gen < 8 || !device->has_context_isolation;
device->compiler->supports_shader_constants = true;
device->compiler->compact_params = true;
/* Broadwell PRM says:
*

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@@ -2799,6 +2799,7 @@ __DRIconfig **intelInitScreen2(__DRIscreen *dri_screen)
!(screen->kernel_features & KERNEL_ALLOWS_CONTEXT_ISOLATION);
screen->compiler->supports_pull_constants = true;
screen->compiler->compact_params = true;
screen->has_exec_fence =
intel_get_boolean(screen, I915_PARAM_HAS_EXEC_FENCE);